Hoist drum



Feb. 24, 1925. 1,527,478

I D. B. HARPER HOIST DRUM Filed April 17, 1924 ATTORNEYS Patented Feb. 24, 1925.

UNITED STA TES PATENT OFFICE DWIGHT B. HARPER, 0F RIVER FOREST, ILLINOIS.

HOIST DRUM.

Application filed April-17, 1924. Serial No. 707,253.

Illinois, have invented a new and useful Improvement in Hoist Drums, of which the 1following is a full, clear, and exact descrip- My invention relates to improvements in hoist drums, and consists in the'combinations, constructions, and arrangements herein described and claimed.

An object of my invention is to provide a hoist drum in which an auxiliary storage compartment is provided for the storage of cable not intended for immediate use, thereby precluding flattening of the cable layers ordinarily and necessarily permitted to remain adjacent the core of the ordinary type of hoist drum. I have found that the strength of that portion of the cable normally maintained adjacent to the core of a hoist drum where almost constant pressure is brought to bear upon the cable, is noticeably use.

. due to reduced, due to the fact that the cable becomes flattened and materially weakened at this point.

A further object of my invention is to provide a hoist drum of the type described in which means is provided for maintaining substantially uniform circumferential dimensions of the cable always wound upon the drum, and hence a uniform cable speed. This is particularly advantageous where the hoist is employed for use with a clam-shell.

A further object of my invention is to provide a device of the typedescribed in which the additional cable is at all times available and which is easily accessible for A further object of my invention is to provide a hoist drum of the type described 1n which the cable may be automatically rewound in the storage portion of the drum; particularly novel construction of the hoist drum. 7

Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in the appended claim.

My invention is illustrated in the accompanying drawings forming part of this apvplication, in which Figure 1 is a sectional view of an embodi li for immediate use is wound upon the drum L 2 and the remainder is projected through ment of my invention, and

Figure 2 is a sectional 2-2 of Figure 1.

In carrying out my invention I make use of a driven shaft 1 which may be driven by any ordinary type of hoist engine or motor having a control by means of which the shaft 1 may idle relative to'the hoist engine or motor.

An inner drum 2 is keyed at 3 to the shaft 1 so as to rotate therewith. The inner drum 2 is provided with radially extending side walls {1 and 5 respectively at each end view along the line thereof. The side walls 4 and 5 are formed with relatively broad peripheral edges 6 and 7 respectively, forming a bearing for an outer drum 8.

This outer drum 8 is free to rotate upon the bearing surfaces formed by the peripheral edges 6 and 7 of the walls of the drum 2. The outer drum 8 has radially extending side walls 9 and 10 respectively at its opposite ends so as to confine a cable Wound thereupon.

The wall 4: of the inner drum 2 has a radially extending flange 11 at the outermost end of the peripheral edge 6 thereof. This is forthe purpose of limiting the lateral movement of the drum 8 in one direc' tion so that the drum 8 may be aligned with the drum 2. A locking ring 12 is secured to thewall 5 of the drum 2 by means of bolts 13 which may be removed to permit the'ring 12 to be taken ofl'.

Means for locking the drum 8 against movement relative to the drum 2-is provided in a sliding key 15 projected through the flange 11 and arranged to be received in a socket 16 disposed in the wall 9 of the drum 8. When the key 15 is in the position shown in full lines of Figure 1, the drum 8 must may be disposed upon the portion 19 of the cable to cable.

That portion of the cable 17 not desired prevent inward movement of the ted lines in Figure a longitudinally extending slot 21 (see Figure 2), in the drum 2. The side Walls of this slot are disposed obliquely relative to the adjacent radii of the drum 8 so that the cable may travel in a substantially straight path from the drum 2 to the drum 8, and vice versa. This slanting of the opening 21 prevents cutting and undue mutilation of the cable.

From the foregoing description of the various parts of the device, the operation thereof maybe readily understood. As ordinarily used, the length of the cable extending from a hoisting drum to the work engaging part of the cable carried by the drum varies from time to time, according to the depth or distance from which the load is lifted or pulled. It is common practice to use the cable long enough for the maximum lift, as for the operation of a clam-shelL-boom hoist, crane, or the like, and winding the entire amount of cable on the active surface of the drum. It may be readily seen that there is a large portion of the time as when a short lift is repeated many times that this excess cable constitutes a serious handicap to successful and rapid operation by becoming'slack, crosswound, or tangledin the machine adjacent to the hoist drum, as well as materially weakening and flattening the cable by pressure brought to bear thereupon by the active portion of the cable.

By the use of my improved hoisting drum, the handicap of excess cable is obviated by means of storing the cable when not in use on an inner drum in such a manner as to be available for use at all times and thereby leave the outer Winding drum 8 free to handle the active portion of the cable.

Let us assume now that it is desired to use more cable upon the active or outer drum 8 than is at present in use. To this end the operator will release the locking pin 15 so as to move it to the position shown in dot- 1 and permit the shaft 1 to rotate slowly. The load will carry the cable which must he at this time entirely removed from the outer drum 8 directly from the drum 2 through the slotted opening- 21. The drum 8 will remain stationary during this process.

When sufficient additional cable is thus made available, the locking pin 15 is moved to the position hoist drum employed in precisely the same manner as the ordinary type of hoist drum.

If it is desired now to shorten the'length of active cable upon the drum 8, the pin 15 is again moved to the position shown in dotted lines, and power applied to drive the shaft 1 so as to wind the cable directly upon the hoist drum 2. As before, prior to this act, all cable must be removed from the drum 8 so that the cable may pass directly through the opening 21 upon the drum 2.

When it is desired to remove the drum 3 from the drum 2, the locking ring 12 is removed by the withdrawal of the bolts 13 and the entire drum 8 moved laterally from its support upon the drum 2.

I claim:

A hoist drum of the type described comprising a shaft, an inner drum carried upon said shaft and arranged to turn therewith, an outer drum rotatably mounted concentric with said inner drum on the peripheral side walls of said inner drum, thereby pro- Viding a compartment between the cable supporting wall of the inner drum and the inner wall of the outer drum, and a removable locking ring carried by said inner drum for locking said outer drum against removal therefrom and for permitting the removal of said outer drum at will, a cable fixed at one end of said inner drum and arranged to be wound at will upon said inner drum, the outer end of said cablebeing projected through an opening in the cable bearing wall of said outer drum, and means for locking the drums relatge to one another.

WIGHT B. HARPER.

shown in full lines and the Y 

